The drycleaning process has long been used to clean garments by the use of an organic type solvent The technology of the drycleaning process has improved to the point where machines and apparatus can be purchased with programmers that will control the process from initial cleaning stage through the end of the drying stage. Such functions as solvent let down to the wash wheel, cleaning by batching, cleaning on a filter, solvent level control, solvent pump out to storage tanks or to stills, filter regeneration, clean solvent rinse, extraction, drying, deodorizing and so forth, are frequently programmed on these machines so that the operator merely chooses the correct program for the type of garment or fabric to be cleaned and places the program in the drycleaning programmer and the drycleaning machine cleans and dries the garments.
It is well known in the drycleaning industry that certain additives to the solvent assist the cleaning process and impart other desirable properties to the clean garments. The problem that arises in the use of these additives is that frequently they are expensive and so careful metering of these additives is necessary to prevent excessive costs in using them. Other additives, e.g., water, while not expensive, must be added in carefully controlled amounts to prevent damage to the garments being cleaned. These additives must be added to the drycleaning process at the precise time in order for them to accomplish their intended purpose.
There is a problem with the programmers that are used on drycleaning machines in which the process is controlled by a card or a plastic tab. These cards or tabs have 11 or more tracks with each track controlling one or more functions on the drycleaning machine. The method by which these cards or tabs operate is as described below.
The card or tab is placed in a slot where a mechanical drive mechanism moves it at a constant rate through a sensing area where sensors on each track detect holes (in the case of cards) or depressions (in the case of tabs) which actuates switches to control the functions on a drycleaning machine. The time each function operates is determined by the length of the hole or depression. These cards or tabs are usually cut by hand by the person setting up the process. It is difficult to cut these to an accuracy of greater than plus or minus, 15 seconds, to control a particular function. In practically all cases, the programmers on these drycleaning machines are difficult to control to the precise accuracy necessary to give the exact metering of additives necessary if the metering is done by a constant volume per unit of time. This operation generally calls for an accuracy of plus or minus 1 second.
There is another problem which frequently arises on these programmed machines due to the fact that there are not sufficient spare tracks on the programmer control card or tabs so that the particular chemical can be called for on a separate track. In this case, the track is chosen in which an event is called for at the same time as is necessary to add the additive. This could be the opening of a particular valve, starting of a motor, or closing of a valve or some other event. The requirements of the process could be that this particular event chosen is of longer or shorter duration, due to its process purpose, than the time requirements of the additive feeder at the rate it meters to the drycleaning process.
Because of these problems with the use of the existing programmers on drycleaning machines, it is necessary to have a separate controller to meter in additives to the drycleaning process. This controller, upon receiving a signal from the drycleaner programmer would control devices to meter additives for a predetermined length of time that would be virtually independent of the length of signal that activates it.
Accordingly, an important object of the present invention is to provide a control injecting system which will upon receiving a signal from the drycleaning programmer, and independent of the length of the signal, provide chemicals and/or water to the drycleaning machine for a predetermined time interval.
The present invention provides such a control injecting system by having a circuit in which there is an automatic reset electrical timer having a dial which may be set for the desired time interval during which the chemical and/or water is to be added to the drycleaning machine. In conjuction with the timer, the control circuit has receiving means or a pair of terminals for receiving the signal from the programmer of the drycleaning machine, which activates the timer by relay means or switches and contacts, energizes a metering device to which the control circuit is in communication by load terminals to provide chemicals and/or water to the drycleaning machine for the predetermined time interval.
The invention, together with further objects, features and advantages thereof will be more clearly understood by reference to the following detailed specification taken in conjunction with the accompanying drawings which illustrate a preferred embodiment.